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                  <a href="#id2938516" class="shortcut">Description</a></nobr></td></tr>
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<h2>
<a name="id2938464"></a><span class="refentrytitle">Varargs Value Collection</span>
</h2>
<p>Varargs Value Collection &#8212; Converting varargs to generic values</p>
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<div class="refsynopsisdiv">
<h2>Synopsis</h2>
<pre class="synopsis">

#include &lt;glib-object.h&gt;
#include &lt;gobject/gvaluecollector.h&gt;


union               <a class="link" href="gobject-Varargs-Value-Collection.html#GTypeCValue">GTypeCValue</a>;
#define             <a class="link" href="gobject-Varargs-Value-Collection.html#G-VALUE-COLLECT:CAPS">G_VALUE_COLLECT</a>                     (value, var_args, flags, __error)
#define             <a class="link" href="gobject-Varargs-Value-Collection.html#G-VALUE-LCOPY:CAPS">G_VALUE_LCOPY</a>                       (value, var_args, flags, __error)
#define             <a class="link" href="gobject-Varargs-Value-Collection.html#G-VALUE-COLLECT-FORMAT-MAX-LENGTH:CAPS">G_VALUE_COLLECT_FORMAT_MAX_LENGTH</a>
</pre>
</div>
<div class="refsect1" lang="en">
<a name="id2938516"></a><h2>Description</h2>
<p>
The macros in this section provide the varargs parsing support needed
in variadic GObject functions such as <a class="link" href="gobject-The-Base-Object-Type.html#g-object-new"><code class="function">g_object_new()</code></a> or <a class="link" href="gobject-The-Base-Object-Type.html#g-object-set"><code class="function">g_object_set()</code></a>.
They currently support the collection of integral types, floating point 
types and pointers.
</p>
</div>
<div class="refsect1" lang="en">
<a name="id2938555"></a><h2>Details</h2>
<div class="refsect2" lang="en">
<a name="id2938565"></a><h3>
<a name="GTypeCValue"></a>union GTypeCValue</h3>
<a class="indexterm" name="id2938578"></a><pre class="programlisting">union GTypeCValue
{
  gint     v_int;
  glong    v_long;
  gint64   v_int64;
  gdouble  v_double;
  gpointer v_pointer;
};
</pre>
<p>
A union holding one collected value.
</p>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2938595"></a><h3>
<a name="G-VALUE-COLLECT:CAPS"></a>G_VALUE_COLLECT()</h3>
<a class="indexterm" name="id2938608"></a><pre class="programlisting">#define             G_VALUE_COLLECT(value, var_args, flags, __error)</pre>
<p>
Collects a variable argument value from a va_list. We have to
implement the varargs collection as a macro, because on some systems
va_list variables cannot be passed by reference.
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>value</code></em>&#160;:</span></p></td>
<td>a <a class="link" href="gobject-Generic-values.html#GValue"><span class="type">GValue</span></a> return location. <em class="parameter"><code>value</code></em> is supposed to be initialized 
  according to the value type to be collected
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>var_args</code></em>&#160;:</span></p></td>
<td>the va_list variable; it may be evaluated multiple times
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>flags</code></em>&#160;:</span></p></td>
<td>flags which are passed on to the <code class="function">collect_value()</code> function of
  the <a class="link" href="gobject-Type-Information.html#GTypeValueTable"><span class="type">GTypeValueTable</span></a> of <em class="parameter"><code>value</code></em>.
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>__error</code></em>&#160;:</span></p></td>
<td>a <a
href="./../glib/glib/glib-Basic-Types.html#gchar"
><span class="type">gchar</span></a>** variable that will be modified to hold a <a
href="./../glib/glib/glib-Memory-Allocation.html#g-new"
><code class="function">g_new()</code></a>
  allocated error messages if something fails


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<hr>
<div class="refsect2" lang="en">
<a name="id2938748"></a><h3>
<a name="G-VALUE-LCOPY:CAPS"></a>G_VALUE_LCOPY()</h3>
<a class="indexterm" name="id2938761"></a><pre class="programlisting">#define             G_VALUE_LCOPY(value, var_args, flags, __error)</pre>
<p>
Collects a value's variable argument locations from a va_list. 
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>value</code></em>&#160;:</span></p></td>
<td>a <a class="link" href="gobject-Generic-values.html#GValue"><span class="type">GValue</span></a> return location. <em class="parameter"><code>value</code></em> is supposed to be initialized 
  according to the value type to be collected
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>var_args</code></em>&#160;:</span></p></td>
<td>the va_list variable; it may be evaluated multiple times
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>flags</code></em>&#160;:</span></p></td>
<td>flags which are passed on to the <code class="function">lcopy_value()</code> function of
  the <a class="link" href="gobject-Type-Information.html#GTypeValueTable"><span class="type">GTypeValueTable</span></a> of <em class="parameter"><code>value</code></em>.
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>__error</code></em>&#160;:</span></p></td>
<td>a <a
href="./../glib/glib/glib-Basic-Types.html#gchar"
><span class="type">gchar</span></a>** variable that will be modified to hold a <a
href="./../glib/glib/glib-Memory-Allocation.html#g-new"
><code class="function">g_new()</code></a>
  allocated error messages if something fails


</td>
</tr>
</tbody>
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<hr>
<div class="refsect2" lang="en">
<a name="id2938898"></a><h3>
<a name="G-VALUE-COLLECT-FORMAT-MAX-LENGTH:CAPS"></a>G_VALUE_COLLECT_FORMAT_MAX_LENGTH</h3>
<a class="indexterm" name="id2938913"></a><pre class="programlisting">#define	G_VALUE_COLLECT_FORMAT_MAX_LENGTH	(8)
</pre>
<p>
The maximal number of <a class="link" href="gobject-Varargs-Value-Collection.html#GTypeCValue"><span class="type">GTypeCValue</span></a>s which can be collected for a 
single <a class="link" href="gobject-Generic-values.html#GValue"><span class="type">GValue</span></a>.
</p>
</div>
</div>
<div class="refsect1" lang="en">
<a name="id2938947"></a><h2>See Also</h2>
<p>
<span class="type">GValueTable</span>
</p>
</div>
<div class="refsect1" lang="en">
<a name="id2938966"></a><div class="refsect2" lang="en"><a name="id2938967"></a></div>
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<div class="refsect2" lang="en"><a name="id2938968"></a></div>
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